Polymer films are useful in making a variety of disposable articles because they are relatively inexpensive to manufacture, and can be made to be strong, durable, flexible, soft, and a barrier to aqueous liquids. Examples of such disposable products or articles include, but are not limited to, medical and health care products such as surgical drapes, gowns and bandages, protective work wear garments such as coveralls and lab coats, and infant, child and adult personal care absorbent articles such as diapers, training pants, disposable swimwear, incontinence garments and pads, sanitary napkins, wipes and the like. Other uses of polymeric film materials include geotextiles. It is often highly desirable for polymeric films used in such product applications to be both liquid impervious and breathable.
It is known that breathable films can be prepared by blending an organic or inorganic incompatible filler with a polyolefin-based resin, which is then melted, film-formed and stretched. These films are mainly used as liquid barriers in disposable personal care products, which are discarded immediately after use. However, these breathable films prepared from the polyolefin-based resin are not made from renewable polymer resources and cannot be degraded in the natural environment.
There is an increasing demand for the incorporation of more recyclable and/or degradable components in disposable products, and the design of products that can be disposed of by means other than by incorporation into solid waste disposal facilities such as landfills. As such, there is a need for new materials for disposable absorbent products that generally retain their integrity and strength during use, but after such use, are more efficiently disposable. For example, the disposable absorbent product may be easily and efficiently disposed of by composting. Alternatively, the disposable absorbent product may be easily and efficiently disposed of to a liquid sewage system wherein the disposable absorbent product is capable of being degraded.
While it is possible to enhance the breathability and biodegradability of polymer films separately, enhancing the biodegradability of polymer films without diminishing the breathability of the films is difficult. For example, biodegradable films derived from copolyesters are known in the art. Although these films had high breathability, but they were made from petroleum-derived biodegradable polymers which do not contain any renewable polymer components such as renewable natural polymers.
Accordingly, there remains a need for a composition which can be used to manufacture a biodegradable film which is also breathable and contains a renewable component, for use in making disposable or single-use articles of manufacture.